Method and apparatus for making an improved high surface area fiber

ABSTRACT

The present invention is directed to a high surface area fiber and method for making the same. The fiber includes a co-extruded internal fiber and an external sheath that is washed with a solvent to remove the dissolvable external sheath, the resulting fiber having a longitudinal axis and a cross-section, the cross-section having a middle region and projections extending from the middle region.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/359,619, filed Jan. 27, 2012, which is a divisional application ofU.S. patent application Ser. No. 11/592,370 filed Nov. 3, 2006, now U.S.Pat. No. 8,129,019, issued Mar. 6, 2012, which is incorporated herein byreference.

DESCRIPTION

1. Field of the Invention

The present invention relates generally to high surface area fibers andtextiles made from the same. Further, the present invention relates tohigh surface area fibers made from a bicomponent fiber extrusionprocess.

2. Description of the Prior Art

Fibers capable of absorbing and filtering liquids or particles are knownin the art. Fiber surfaces are often treated chemically or physically toenhance their ability to hold liquids or particles. For instance, inorder to increase the surface area of a fiber the surfaces are maderough to create grooves and channels. Some absorbent fibers known in theart are treated with hydrophobic or hydrophilic chemicals, which affectsfluid flow.

One such fiber that is used for absorption is the 4DG fiber developed byand commercially available from Eastman Chemical Company. Referring tothe drawing of FIG. 1 is a cross-sectional view of the 4DG fiber, alsoknown as surface capillary fibers. The prior art fiber of FIG. 1discloses one set of at least three arms that project from one side ofthe spine to define a first set of grooves, and a second set of at leastthree arms that project from a second side of the spine to define asecond set of grooves. The arms and grooves of the prior art fiber havean irregular geometry so as to create grooves that are deep and narrowenough to transport fluids along the length of the fiber by capillaryaction. Additionally, the prior art fiber of FIG. 1 has a large denierwhich limits its use in certain applications for which nano-fibers arerequired.

The 4DG fiber seeks to increase the depth of the grooves by providing afiber with a specific cross-sectional geometry. However, there areseveral disadvantages to the 4DG fiber and other fibers having a similarconfiguration. Many such fibers cannot be spun to fiber diameters lessthan about 50 to 60 microns, thereby restricting their potentialapplications. The minimum denier attainable with the 4DG fiber isapproximately 3. Furthermore, due to the large grooves between the armsof the fiber, the arms often break during the spinning process. Suchfibers have a limited number of arms and grooves resulting in arelatively low surface to volume ratio, which restricts the amount offluid that can be absorbed. Finally, due to the size and geometry of the4DG fiber, the arms can easily interlock during fabric formationresulting in dense and compressed materials, which diminishes itsfiltration and absorption properties.

There have been many attempts in the past to create special fibers withdeep grooves or channels on the surface to promote surface capillaryproperties. Such fibers utilize multiple legs, typically 8, to form deepchannels on the surface. The surface of these fibers can be treated withappropriate treatments that accommodate and facilitate fluid flow morereadily and are therefore useful for fluid movement. Many of thesefibers have a higher degree of bulk density and are therefore suitablefor insulation applications. Since the arms can capture and trapparticles, they are further useful for filtration applications or forsurface treatments to activate the surface.

Fibers with surface grooves are produced using special spinnerets assingle component fibers. The fibers are extruded and melted, deliveringthe molten polymer through spin beams and the spinneret capillaries toform the desired shape. The fibers are then quenched upon the exit fromthe spinneret and drawn subsequently to form a stronger and finer fiber.However, because of the deep grooves or arms of the fibers, the fiberscannot be made into normal fiber sizes that are preferred and used bythe industry. Most fibers used today are between 1 and 3 denier perfilament, however most fibers with the increased surface areas asdiscussed above are currently typically available in 6 denier or larger.Fibers with deniers of 6 or larger are extremely coarse, more difficultto process, and are therefore, limited in their use.

Traditional single component round fibers are commonly used in the art.The cross-sectional design of a single component round fiber istypically a circle. One problem with single component round fibers isthat in order to increase the surface area of the fiber per mass, thecross-sectional area also has to be reduced, requiring significantreduction in diameter to produce higher surface areas.

There is a need for a fiber with an increased surface area, at least 2to 3 times the surface area of typical fibers known in the art, and withdeep grooves or channels on the surface to promote surface capillaryproperties while maintaining a normal fiber size as used in theindustry. The present invention discloses a fiber with an increasedsurface area and multiple surface channels, while maintaining a similardenier.

The present invention is provided to solve the problems discussed aboveand other problems, and to provide advantages and aspects not providedby prior fibers of this type. A full discussion of the features andadvantages of the present invention is deferred to the followingdetailed description, which proceeds with reference to the accompanyingdrawings.

SUMMARY OF THE INVENTION

An embodiment of the present invention includes a method of making ahigh surface area fiber that includes co-extruding an internal fiber anda dissolvable external sheath through at least one plate. The resultingfiber is then washed with a solvent to remove the dissolvable externalsheath. The resulting fiber has a longitudinal axis and a cross-section,the cross-section having a middle region and between 16 and 32projections extending from the middle region.

Another embodiment of the present invention also includes a method ofmaking a high surface area fiber that includes co-extruding an internalfiber and a dissolvable external sheath through at least one plate. Theresulting fiber is then washed with a solvent to remove the dissolvableexternal sheath. The resulting fiber has a longitudinal axis and across-section, the cross-section having a middle region and a pluralityof projections extending from the middle region, the plurality ofprojections defining a plurality of channels that have a width between200 nanometers and 500 nanometers.

Yet another embodiment of the present invention includes a method ofmaking a high surface area fiber that includes co-extruding an internalfiber and a dissolvable external sheath through at least one plate. Theresulting fiber is then washed with a solvent to remove the dissolvableexternal sheath. The resulting fiber has a longitudinal axis and across-section, the cross-section having a middle region and a pluralityof projections extending from the middle region, and has a specificsurface area of at least 80,000 square centimeters per gram.

Thus, the present invention provides a high surface area fiber made froma bicomponent extrusion process for woven and non-woven applications.

These and other aspects of the present invention will become apparent tothose skilled in the art after a reading of the following description ofthe preferred embodiment when considered with the drawings, as theysupport the claimed invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional perspective view of a prior art fiber.

FIG. 2 is a cross-sectional view of a fiber with an external sheath, inaccordance with one embodiment of the present invention.

FIG. 3 is a cross-sectional view of a single fiber, in accordance withone embodiment of the present invention.

FIG. 4 is a cross-sectional view of a fiber without the external sheath,in accordance with one embodiment of the present invention.

FIG. 5 is a cross-sectional view of the fiber having a circularconfiguration, in accordance with one embodiment of the presentinvention.

FIG. 6 is a cross-sectional view of a non-woven fabric, in accordancewith one embodiment of the present invention.

FIG. 7 is a cross-sectional view of a non-woven fabric of the prior art.

FIG. 8 is a graph comparing the denier per filament versus the specificsurface areas for a round fiber, a 4DG fiber, and a fiber of the presentinvention.

DETAILED DESCRIPTION

In the following description, like reference characters designate likeor corresponding parts throughout the several views. Also in thefollowing description, it is to be understood that such terms as“forward,” “rearward,” “front,” “back,” “right,” “left,” “upwardly,”“downwardly,” and the like are words of convenience and are not to beconstrued as limiting terms. Referring now to the drawings in general,the illustrations are for the purpose of describing a preferredembodiment of the invention and are not intended to limit the inventionthereto.

Referring to the drawings, FIGS. 2-4 disclose a cross-section of thefiber of the present invention generally designated by the referencenumeral 10. As shown in FIG. 2, the fiber 10 generally comprises aninternal fiber 12 and an external sheath 14. The fiber 10 is generallyconstructed from two different polymer compositions that can be extrudedin an oval cross-section, which allows for high processability.Alternatively, the cross-section can be circular or other shapes asdesired. The extrusion process and the method of making the fiber 10 ofthe present invention are described in greater detail below.

As further shown in FIGS. 2-4, the cross-section of the internal fiber12 has a generally winged-shape, or amoeba-like shape. The internalfiber 12 has a middle region 16, which is the longitudinal axis 17 thatruns down the center of the internal fiber 12. The longitudinal axis 17has a plurality of projections 18 that extend from the longitudinal axis17, which are depicted in FIGS. 2-4. In the preferred embodiment, theplurality of projections extend along the periphery of the longitudinalaxis 17. Alternative cross-sectional shapes, such as but not limited toa circular-shape or the like, would have the middle region 16 formed asa hub where the projections extend from the hub. In one embodiment, theplurality of projections are uniformly spaced. The plurality ofprojections 18 increase the surface areas and surface capillaries for asingle fiber. In the preferred embodiment, the plurality of projections18 define a plurality of channels 20, as shown in FIG. 4. In oneembodiment, the plurality of channels 20 are uniformly spaced. Thechannels 20 create a surface capillary portion along the length of thefiber 10 that facilitates the absorption of liquids within the fiber 10.Additionally, the channels 20 allow particles, such as debris and dirt,to be picked-up and retained within the fiber 10. Thus, the fiber of thepresent invention has a plurality of longitudinal capillary channels 21that extend along the length of the fiber as shown in FIG. 3. Thepresent invention also drastically increases the surface area of thecross-section of the internal fiber 12 due to the plurality ofprojections 18. The increased surface area created by the internal fiber12 depends on the number of segments that are used during themanufacturing of the fiber 10, which is discussed in detail below.

Preferably, the channels 20 are nano-sized, having a width of about 200nanometers. Alternatively, the channels 20 could be between 200nanometers to 1000 nanometers. The width of the channels 20 can bemodified to fit different applications. The nano-sized channels of thepresent invention allow the fiber 10 to be used in applications wheremicro-filtration or micro-absorption is necessary. For example, certainfiltration mechanisms require a channel size of about 300 nanometers.Because the channel size for each fiber can be regulated, the presentinvention can be used to create a textile fabric having fibers withdifferent channel sizes. For example, a textile fabric such as a filtercould comprise fiber bundles having 200 nanometer channels and 500nanometer channels. In one embodiment if the channels have a width ofabout 200 nanometers there are about 32 projections 18 extending fromthe middle section 16.

In the preferred embodiment of the present invention, the internal fiber12 is a thermoplastic polymer known in the art. Any number ofthermoplastic polymers can be used, such as but not limited to,polypropylene, polyester, nylon, polyethylene, thermoplastic urethanes(TPU), copolyesters, or liquid crystalline polymers.

In the preferred embodiment the cross-section of the fiber is highlyflexible and has a solid interior. Alternatively, in one embodiment, theinterior, or middle region part of the internal fiber is a void. Thevoid in the center forms an added channel for fluid flow. FIG. 5 shows across-section of a fiber of the present invention missing the middleregion 16 of the internal fiber 12.

Alternatively, in another embodiment, the middle region 16 of theinternal fiber 12 can be formed into a circular configuration during theextrusion process. This void allows the internal fiber 12 to be morerigid and have more bending resistance because of the void in thecenter. Additionally, the void in the center forms an added channel forfluid flow. A fiber with a circular cross section with a void will havea lower tendency to bend over itself.

FIG. 2 shows a cross-sectional view of the fiber 10 with the externalsheath 14. In the preferred embodiment the external sheath 14 is adissolvable thermoplastic, such as but not limited to, polyactide (PLA),co-polyester (PETG), polyvinyl alcohol (PVA), or ethylene-vinyl alcoholcopolymer (EVOH). It is contemplated that any number of dissolvablethermoplastics known in the art may be used as the external sheath 14 inconnection with the present invention. In the preferred embodiment theexternal sheath 14 encompasses the internal fiber 12 as shown in FIG. 2.

One aspect of the present invention is increasing the surface area ofthe fiber, while maintaining the denier of the fiber between 1 and 3. Inthe preferred embodiment, the denier of the fiber is about 1.0 to about2.0. However, alternatively, the denier of the fiber can range fromabout 1.0 to about 20.0.

Denier is the unit used to measure the fineness of yarns, and is equalto the mass in grams of 9,000 meters of yarn. In the preferredembodiment of the present invention, the specific surface area for a one(1) denier fiber is about 28,000 and about 200,000 cm2/g. The specificsurface area in terms of cm2/g of a fiber is measured by the followingequation:

${{Specific}\mspace{14mu} {Surface}\mspace{14mu} {Area}} = {\text{?}\sqrt{\left( \frac{4\; \pi \; L}{\rho \times {Denier}} \right)}}$Where$\text{?} = {{{Shape}\mspace{14mu} {Factor}} = \frac{P^{2}}{4\; \pi \; \text{?}}}$where L = Length, K  9 × 10?  cm${\rho = {Density}},{K\mspace{14mu} 1.38\frac{g}{{cm}\text{?}}}$Denier = Linear  Density P = Perimeter A = Cross  Sectional  Area?indicates text missing or illegible when filed                    

The specific surface area of the preferred embodiment of the presentinvention is about 57-60 times greater than a typical 4DG fiber known inthe art. As shown in FIG. 8, the specific surface area of a fiber of thepresent invention is significantly greater than a traditional roundfiber or a typical 4DG fiber having the same denier. For example, around fiber with a denier of 3 has a specific surface area of 1653cm2/g. A 4DG fiber with a denier of 3 has a specific surface area of4900 cm2/g. In contrast, a fiber of the present invention with a denierof 3 has a specific surface area of over about 80,000 cm2/g. In oneembodiment of the present invention, the cross-section of the internalfiber has a specific surface area of about 140,000 cm2/g or higher. Thepresent invention achieves a large specific surface area because of theunique geometry of the plurality of projections and the plurality ofchannels. While the preferred embodiment of the present invention has afiber denier of about 1.0 to about 2.0, the above comparison was chosenbecause the 4DG fiber is not capable of being produced with a denierbelow 3.

In the preferred embodiment, the internal fiber 12 has a cross-sectionallength of about 20 micrometers and a cross-sectional width of about 10micrometers, which yields a fiber having a denier of about 1.5. Denierrefers to the linear density of the fiber and is the weight in grams fora fiber measuring 9,000 meters. In another embodiment, the internalfiber 12 has a cross-sectional length of about 10 micrometers and thewidth of about 10 micrometers. The internal fiber 12 of the presentinvention may have a cross-sectional length of about 1 micrometer toabout 100 micrometers and a cross-sectional length of about 1 micrometerto about 100 micrometers. Alternatively, in another embodiment of thepresent invention the fiber could have a denier of 3 or more, whichwould provide larger fiber with significantly large surface areas.

The method of making the fiber of the present invention uses extrusiontechniques known in the art. Typically, bicomponent fibers are formed bycoextruding or, extruding two polymers from the same spinneret with bothpolymers contained in the same filament or fiber. The extrusion processforces thick, viscous polymers through a spinneret to form semi-solidfibers. In the preferred embodiment of the present invention, theextrusion system will form the fibers as described by directing andchanneling the two polymers appropriately, resulting in a more uniformshape. The number of holes on the plates correspond to the number ofsegments present in the fiber. These filaments are then solidified. Thepreferred embodiment of the present invention uses melt spinning to formthe fibers, however other methods known in the art can be used. Forexample, a segmented pie extrusion system can be used to form fiberswith projections extending from the longitudinal axis by a carefulselection of the two polymers and control of the extrusion process.

The method of making the preferred embodiment begins by extruding abicomponent fiber comprising a thermoplastic polymer, the internalfiber, and a dissolvable thermoplastic polymer, the external sheath. Thebicomponent fiber is extruded through a spinneret having any number ofdesired holes and cross-sectional shapes. In the preferred embodimentthe cross-section of the spinneret is oval for high processability,alternatively a round cross-section can also be used, or other desiredshapes.

Alternatively, the final cross-sectional shape of the fiber, thewinged-shape as discussed above, is determined by the number of segmentsformed from the extrusion process. The segments resemble pie-pieces,called a “segmented-pie” bicomponent fiber. Typical fibers of the priorart are formed from 16 segments, however in order to achieve the highsurface area cross-section of the present invention, the fiber must haveat least 4 segments.

In one embodiment of the present invention, the extruded bicomponentfiber has at least 4 segments. Alternatively, in another embodiment ofthe present invention the winged-shape cross-section of the internalfiber yields extremely high surface areas because it is formed from abicomponent fiber having 64 segments. A caterpillar-like shape, as shownin FIGS. 2-4, was an unexpected result generated by a 64 segmented-pieextrusion. It is difficult to form a bicomponent fiber having more than24 segments and the prior art fibers are limited in the number ofsegments they can have.

One way to control the shape and the size of the segments is by changingthe temperature, viscosity, or pressure of the bicomponent fiber duringthe extrusion process. Melt spinning allows fibers to be extruded fromthe spinneret in different cross-sectional shapes, such as round,trilobal, pentagonal, octagonal, and other shapes. The bicomponentsegments of one embodiment of the present invention resemble a segmentedpie having anywhere up to 64 pie segments. In the preferred embodimentthe segments alternate between the internal fiber and the dissolvableexternal sheath. It is important that the segments alternate becauseonce the external sheath is washed and removed, the remaining segmentsdefine the plurality of projections that form the basis for absorptionand filtration. The number of projections is directly proportional tothe total surface area generated. Therefore, fibers with precise andpre-determined surfaces can be formed.

In a preferred embodiment, after the bicomponent fiber is extruded andmelt spun, the bicomponent fiber can be formed into a textile product.Alternatively, the textile product comprises fiber media that is made ofa bicomponent fiber. The bicomponent fiber can be bonded together toform a nonwoven fabric, such as a filter. Alternatively, the bicomponentfiber can be formed into a woven fabric, such as a garment. One of theadvantages of the present invention is that the external sheath does nothave to be removed until after the textile media is made. This enhanceshandling of the fiber and reduces costs associated with manufacturing.FIG. 6 shows a non-woven fabric of the present invention and illustrateshow the winged-shaped fibers assemble together. As shown in FIG. 6, thefibers can be compressed closely together to form bundles withoutinterlocking when they are placed adjacent to each other due to thegeometry of the fiber and the size of the channels. Additionally,because the textile fabric can be constructed when the external sheathis still on, the sheath further prevents the fibers from interlockingwith one another. FIG. 7 shows a prior art fabric in which the fibersinterlock. Because the fibers of the present invention do not interlocklike other fibers known in the prior art, the effectiveness of thechannels of the present invention is not compromised and remainsavailable for absorption or filtration. The external component can beremoved after the final product is formed. Therefore, the fibers of thepresent invention and their projections cannot interlock.

Once the textile product is formed, the fabric is washed with a solventsuch as, but not limited to, NaOH, acids or in the case of waterdispersible polymers such as Exceval, water is used in order to removethe soluble external sheath. Alternatively, the bicomponent fiber can bewashed prior to forming the textile product if desired.

In order to form the nonwoven fabric of the present invention, thefibers can be bonded by using several different techniques includingthermal, chemical, or mechanical bonding. In one embodiment, thenonwoven fabric is formed by using hydroentanglement, which is amechanism used to entangle and bond fibers using hydrodynamic forces.Alternatively, nonwovens can be created by needle punching whichmechanically orientates and interlocks the fibers of a spunbound orcarded web. Needle punching is achieved with thousands of barbed feltingneedles repeatedly passing into and out of the web. Needle punching andhydroentanglement form a dense structure so that when the externalsheath is removed, the wings will release in place forming a structurewith high permeability. The ultimate application of the fabric willdetermine which bonding technique should be utilized. For example, ifthe nonwoven fabric is to be used for filtering large particles, it canbe made using spunbound fibers that are randomly interlocked fibers, butnot woven. If the non-woven fabric is needed to filter smallerparticles, then it can be made from melt blown fibers, which uses highvelocity air or another appropriate force to bind the fibers together.Alternatively, filaments can be extruded, and said filaments can becrimped and cut into staple fibers from which a web can be formed andthen bonded by one or more of the methods described above to form anonwoven. Same staple or filament fibers can be used to form woven,knitted or braided structures as well.

In another embodiment of the present invention, staple nonwoven fabricscan be constructed by spinning the bicomponent fiber and cutting thelength of the fiber into short segments and put into bales. The balesare then spread in a uniform web by a wetlaid process or carding, andare subsequently bonded by thermo-mechanical means as known in the art

The fiber of the present invention can also be used to manufacturetraditional woven fabrics for use in garments and the like. Because thefibers of the present invention are strong, they can be. used intraditional knitting and braiding techniques without compromising theintegrity of the fiber.

Although numerous fibers are known in the art, the present inventiondiscloses a high surface area fiber with a small denier that can be usedin application for both woven and non-woven fabrics. The fibers of thepresent invention have higher thermal insulation capabilities thantraditional fibers known in the art, and form improved filtrationmediums. Furthermore, the fibers of the present invention are stronger,more flexible, and more breathable. As discussed above, because thewinged-shaped fibers are compression resilient, the channels are notobstructed and have greater capillary/wicking abilities, as well asabsorption capabilities. Additionally, these fibers have the ability tocapture nano-sized particles. Because the fibers of the presentinvention are strong and have shear resistance, the fibers can withstandhigh pressures and can be used in liquid filtrations as well asdemanding aerosol filtration applications requiring high pressure. Assuch, the present invention provides for a high-efficiency low-pressuredrop filter constructed from woven or nonwoven fabrics or fibers.

There are numerous applications of the present invention. In one examplethe present invention can be used in traditional woven applications,such as wicking garments, thermally insulating garments, comfortgarments, sportswear and camping wear. In another example, the presentinvention can be used in non-woven fabrics to produce filter media tofilter liquids or air for cleaning rooms. In yet another example, thepresent invention can be used with traditional round fibers to yieldmulti-layer fibers that can be combined using a spinneret or combinedlater in the manufacturing process. Combining or sandwiching the fibersof the present invention with traditional round fibers allows a singleproduct to have multiple physical properties, and is cost effective.

The present invention can also be used for improved wipe materials. Intypical applications wipes are primed with liquids before use, such asin baby wipes. However, the present invention allows the ability tocreate a wipe product that will pick up dirt and dust particles withoutleaving behind any particles because the liquid in the channels of thefibers remains there while still dissolving and aiding the clean-upprocess. Additionally, the present invention can be used for hygiene andacoustic materials, thermal insulation, geotextile materials,construction materials, and compressive performance materials such asseat cushions and mattresses.

Certain modifications and improvements will occur to those skilled inthe art upon a reading of the foregoing description. The above-mentionedexamples are provided to serve the purpose of clarifying the aspects ofthe invention and it will be apparent to one skilled in the art thatthey do not serve to limit the scope of the invention. All modificationsand improvements have been deleted herein for the sake of concisenessand readability but are properly within the scope of the followingclaims.

What is claimed is: 1-28. (canceled)
 29. A winged fiber comprising: aninternal fiber having a cross-section and comprising a middle region,the middle region having between 16 projections and 32 projectionsextending from the middle region and along a periphery of the middleregion; wherein, the winged fiber has a denier in the range of 1-20 anda specific surface area between 28,000 cm²/g and 1,000,000 cm²/g. 30.The winged fiber according to claim 29 wherein the internal fibercomprises at least one thermoplastic polymer.
 31. The winged fiberaccording to claim 29 wherein the middle region is hollow forming a hubwith the projections extending outwardly therefrom.
 32. The winged fiberaccording to claim 29 wherein the projections define channels betweenthe projections, and wherein the channels have a channel width ofbetween 200 nanometers and 1000 nanometers.
 33. The winged fiberaccording to claim 29 wherein the winged fiber has a cross-sectionallength of between 10 micrometers and 50 micrometers and across-sectional width between 5 micrometers and 50 micrometers and ashape factor of at least
 10. 34. The winged fiber according to claim 29wherein the winged fiber further comprises an external sheath, whereinthe external sheath encompasses the internal fiber, and wherein theexternal sheath is dissolvable.
 35. A winged fiber comprising: aninternal fiber having a cross-section comprising a middle region, themiddle region having between 16 projections and 32 projections extendingfrom the middle region and along a periphery of the middle region;wherein, the winged fiber has a cross-sectional length between 10micrometers and 50 micrometers and a cross-sectional width between 5micrometers and 50 micrometers and a specific surface area between28,000 cm²/g and 1,000,000 cm²/g.
 36. The winged fiber according toclaim 35 wherein the internal fiber comprises at least one thermoplasticpolymer.
 37. The winged fiber according to claim 35 wherein the middleregion is hollow forming a hub with the projections extending outwardlytherefrom.
 38. The winged fiber according to claim 35 wherein theprojections define channels between the projections, and wherein thechannels have a channel width of between 200 nanometers and 1000nanometers.
 39. The winged fiber according to claim 35 wherein thewinged fiber has a denier in the range of 1-20.
 40. The winged fiberaccording to claim 35 wherein the winged fiber has a cross-sectionallength of between 10 micrometers and 50 micrometers and across-sectional width between 5 micrometers and 50 micrometers and ashape factor of at least
 10. 41. The winged fiber according to claim 35wherein the winged fiber further comprises an external sheath, whereinthe external sheath encompasses the internal fiber, and wherein theexternal sheath is dissolvable.
 42. A winged fiber comprising: aninternal fiber having a cross-section comprising a middle region, themiddle region having between 16 projections and 32 projections extendingfrom the middle region and along a periphery of the middle region;wherein, the winged fiber has a cross-sectional length of between 10micrometers and 50 micrometers and a cross-sectional width between 5micrometers and 50 micrometers and a shape factor of at least
 10. 43.The winged fiber according to claim 42 wherein the internal fibercomprises at least one thermoplastic polymer.
 44. The winged fiberaccording to claim 42 wherein the middle region is hollow forming a hubwith the projections extending outwardly therefrom.
 45. The winged fiberaccording to claim 42 wherein the projections define channels betweenthe projections, and wherein the channels have a channel width ofbetween 200 nanometers and 1000 nanometers.
 46. The winged fiberaccording to claim 42 wherein the winged fiber has a denier in the rangeof 1-20 and a specific surface area between 28,000 cm²/g and 1,000,000cm²/g.
 47. The winged fiber according to claim 42 wherein the wingedfiber further comprises an external sheath, wherein the external sheathencompasses the internal fiber, and wherein the external sheath isdissolvable.
 48. A winged-fiber, the cross-section of the fibercomprising: a middle region having between 16 projections and 32projections and between 16 channels and 32 channels; wherein theprojections extend from the middle region along the periphery of themiddle region; and wherein the projections define the channels, andwherein the channels have a channel width of between 200 nanometers and1000 nanometers.
 49. The winged fiber according to claim 48 wherein themiddle region comprises at least one thermoplastic polymer.
 50. Thewinged fiber according to claim 48 wherein the middle region is hollowforming a hub with the projections extending outwardly therefrom. 51.The winged fiber according to claim 48 wherein the winged fiber has across-sectional length of between 10 micrometers and 50 micrometers anda cross-sectional width between 5 micrometers and 50 micrometers and ashape factor of at least
 10. 52. The winged fiber according to claim 48wherein the winged fiber has a denier in the range of 1-20 and aspecific surface area between 28,000 cm²/g and 1,000,000 cm²/g.
 53. Thewinged fiber according to claim 48 wherein the winged fiber furthercomprises an external sheath, wherein the external sheath encompassesthe middle region, and wherein the external sheath is dissolvable.